Mehmet Gencturk

Various Cranial and Orbital Imaging Findings in Pediatric Abusive and Non-abusive Head trauma, and Relation to Outcomes

Background and PurposeDifferentiating Abusive Head Trauma (AHT) from Non-abusive Head trauma (NAHT) has profound clinical prognostic and legal implications, as certain imaging findings can individually be more suggestive of NAHT, while others are more suggestive of AHT. This study was set out to evaluate for an association between the various imaging findings in AHT with outcome.Material and MethodsOver 7-years, 55 children (age 0-4 years’) with head trauma and magnetic resonance imaging (MRI) were included as either: abusive (n = 16), non-abusive (n = 35), or indeterminate (n = 4). Two pediatric neuroradiologists jointly reviewed the imaging. The frequency of imaging findings and their association with ≥6 months’ outcome were calculated.ResultsComparing abusive versus non-abusive head trauma, complex subdural hematoma was present in 81% (n = 13/16) and 29% (n = 10/35), hypoxic-ischemic injury in 44% (n = 7/16) and 6% (n = 2/35), and diffuse axonal injury in 12% (n = 2/16) and 26% (n = 9/35), respectively. Susceptibility-weighted imaging (SWI) retinal hemorrhages were absent in non-abusive trauma (0/35), but present in 44% (n = 7/16) of the abusive group. In abuse, simple subdural hematomas were absent. Significant associations were found between the presence of abusive trauma with both hypoxic ischemic insult (OR = 12.83, p = 0.0024) and complex subdural hematoma (OR = 10.83, p = 0.0007). The presence of hypoxic ischemic injury (HII) did correlate significantly with clinical outcome (p = 0.017), while retinal hemorrhages on SWI and complex subdural hematoma did not (p = 0.1696-p = 0.2496).ConclusionNeuroimaging findings can be helpful in discriminating these two conditions on presentation, as well as in helping solidify the suspicion of AHT. Regarding eventual outcome in AHT, the most important predictor is clearly HII.

Pretreatment quantitative 18F-FDG PET/CT parameters as a predictor of survival in adenoid cystic carcinoma of the salivary glands

PURPOSE The aim of this study was to determine the unique prognostic value of quantitative 18F-FDG PET/CT parameters to assess progression-free survival (PFS), distant metastasis-free survival (DMFS), and overall survival (OS) in patients with salivary gland adenoid cystic carcinoma (ACC). METHODS We performed a retrospective study including 23 patients (15 men, 8 women; median age, 58 years; range, 21-91 years) with salivary gland ACC between January 2009 and October 2017 who underwent 18F-FDG PET/CT scan prior to treatment. Maximum, mean, peak, tumor-to-mediastinal blood pool and tumor-to-liver standardized uptake values (SUVmax, SUVmean, SUVpeak, SUVratio[med] and SUVratio[liver]), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were obtained from 18F-FDG PET/CT. The prognostic value of quantitative 18F-FDG PET/CT parameters and other clinicopathological variables were evaluated utilizing the Cox proportional regression analysis. RESULTS The 3-year and 5-year OS for all the patients were 90.9%, and 62.3%, respectively. Log rank test determined that the SUVratio[med], SUVratio[liver], MTV and TLG were predictive factors of DMFS, PFS, and OS (p < 0.05), furthermore, SUVmax, minor salivary gland tumors and DM at initial diagnosis (M1 stage) were predictor for PFS; M1 stage and overall stage 3-4 predicted DMFS (all p < 0.05). Cox regression analyses confirmed that the higher SUVratio[med], SUVratio[liver], MTV, and TLG values predicted DMFS, PFS and OS independently, whereas SUVmax was an independent predictor of only PFS (p < 0.05). CONCLUSIONS The pretreatment metabolic 18F-FDG PET/CT parameters may reflect tumor aggressiveness in patients with salivary gland ACC and may potentially be utilized as a prognostic biomarker.

Head/Neck and Spine Imaging Variants: Introduction

This book is separated into six different sections based on regional anatomy for the purpose of addressing the common modalities (such as CT or MRI), imaging sequences (particularly various MR sequences), and protocols (such as slice thickness or windowing) in order to identify each imaging variant in that region. These include: Sinonasal Variants (Chap. 2), Orbital Variants (Chap. 3), Head and Neck Variants (Chap. 4), Temporal Bone Variants (Chap. 5), Cervical and Thoracic Spine Variants (Chap. 6), and Lumbar Spine Variants (Chap. 7). Notably, the Head and Neck Variants chapter covers a wider range of anatomy and physiology (e.g., mucosal abnormalities, thyroid variants, salivary gland variants, Eagle syndrome, vascular variants and PET-CT variants) and thus is a bit more cursory because of the way neck CT imaging is routinely interpreted; perhaps this will be expounded on further in future editions, since some topics are quite vast in that region, and the anatomy is relatively compact. Furthermore, each of the above-mentioned six subjects tend to be subdivided further by sub-anatomic regions (e.g., “ossicular variants” within the Temporal Bone Variants chapter, “lacrimal gland” within the Orbital Variants chapter), and thus the variants of such regions are grouped together so that the differential diagnosis for true pathology and comparison to a known variant is practical; i.e. so a confident identification of the variant can be reached during routine image interpretation. Relevant references are provided for each subject. The goal of this text was to provide a quick, pictorial review with critical anatomy and imaging characteristics to facilitate prompt recognition of each variant; the reader is encouraged to review any of the numerous references included in each section for more in-depth learning.

Neck Soft Tissue Variants

There are multiple developmental variations of soft-tissue neck structures that can be detected on computed tomography (CT), magnetic resonance imaging (MRI), and 18 fluro-deoxy-glucose position emission tomography (FDG-PET). These need to be recognized and differentiated from actual pathologies. There can also be benign lesions involving the soft tissue neck that are caught incidentally while the study is obtained to evaluate other pathologies. Being aware of these variations and certain common benign lesions is quite important. If such variants or “don’t touch lesions” are diagnosed correctly, this can prevent unnecessary patient anxiety, possible invasive procedures, and potential complications. For example, being knowledgeable about the common FDG-PET findings of brown fat activation-related FDG uptake in certain parts of the body prevents misdiagnosis of disease progression and possibly unnecessary biopsies.

Temporal Bone Variants

Temporal bone imaging has a well-deserved reputation as being one of the more challenging aspects of radiology. To paraphrase a neurotology colleague, an amazing amount of intricate anatomy is packed into a very small box. Furthermore, the pathology affecting these structures can be very subtle and affect minute areas. Understanding the myriad appearances of normal structures in unusual places or of unexpected size is quite important. Frequently, these variations are of no consequence but occasionally a similar structure of a comparable size and location that is asymptomatic in one person may be problematic in another.

Normal Variants of the Lumbar and Sacral Spine

Normal variants of the lumbar spine are well described but can simulate pathology if not recognized and understood.

Cervical and Thoracic Spine: Normal Variants and Artifacts

Imaging of the cervical spine is a routine part of a radiology practice. Familiarity with the appearance of the cervical and thoracic spinal vertebrae is critical to providing accurate imaging interpretation. In particular, the complex development of the spine, particularly the cervical spine, merits attention to aid in recognition of spinal normal anatomic variants.

Imaging features of sinonasal tumors on positron emission tomography and magnetic resonance imaging including diffusion weighted imaging: A pictorial review

INTRODUCTION Sinonasal inflammatory conditions account for a major component of head and neck pathologies, whereas neoplasms involving the sinonasal region make up only 2-3% of all head and neck lesions. The symptoms of sinonasal tumors are nonspecific; imaging plays a critical role in distinguishing benign and malignant disease and may illustrate characteristic radiological features of specific sinonasal tumors. OBJECTIVE Aim was to determine the utilization of multimodality imaging, specifically the metabolic information provided by 18-fluorodeoxyglucose positron emission tomography (18F-FDG PET/CT) and diffusivity characteristics seen with diffusion weighted images (DWI) of magnetic resonance imaging (MRI), in a wide range of benign and malignant sinonasal tumors drawn from over 200 sinonasal lesions from our institution and supplemented by the literature. CONCLUSION In this pictorial essay, we have reviewed common imaging characteristics of frequently encountered in sinonasal tumors and divided them into benign and malignant categories to facilitate creation of focused differential diagnoses.

FDG-PET/CT for Assessing the Response to Neoadjuvant Chemotherapy in Bladder Cancer Patients

Micro‐Abstract The purpose of this study was to assess the accuracy of 18F‐fluorodeoxyglucose with positron emission tomography and computed tomography (FDG‐PET/CT) scans in measuring the response to neoadjuvant chemotherapy (NAC) in patients with muscle invasive bladder cancer. FDG‐PET/CT had 78.5% sensitivity (95.6% specificity) in identifying complete pathologic response and 83% sensitivity (94% specificity) for the detection of chemosensitive tumors. FDG‐PET/CT can help determine the response of primary tumor to NAC in patients with muscle‐invasive bladder cancer and thus can more accurately predict prognosis. Purpose To determine the accuracy of 18F‐fluorodeoxyglucose with positron emission tomography and computed tomography (FDG‐PET/CT) scans in assessing the response to neoadjuvant chemotherapy (NAC) in patients with bladder cancer scheduled to undergo radical cystectomy (RC). Patients and Methods All patients treated at our center for muscle‐invasive bladder cancer (MIBC) were counseled and offered NAC before RC. FDG‐PET/CT scans were performed before the initiation of chemotherapy and after completion of the regimen. Patients with disease with complete response to NAC were those who had (pT0) or residual carcinoma‐in‐situ (pTis) on final pathology. Those who were downstaged from MIBC to non‐MIBC were considered to have a chemosensitive tumor. We used percentage reduction in standardized maximum uptake value (SUVmax) from PET/CT scans as our measure to correlate with the final pathology after cystectomy. Results Thirty‐seven patients with MIBC who underwent NAC followed by RC were included in the final analysis. FDG‐PET/CT had 75% sensitivity (89.66% specificity) in identifying those with complete pathologic response with a 100% change in SUVmax, and 83% sensitivity (94% specificity) for the detection of chemosensitive tumors. Conclusion FDG‐PET/CT can help determine the response of primary tumor to NAC in patients with MIBC and thus can more accurately predict the prognosis of the patients, or potentially the appropriate time for cystectomy.